I am biting the bullet & going to sidemount from backmount. I tried to find a set of Worthington LP85's,... but was unsuccessful. So,.... I now have a set of Faber (Blue steel) galvanized cylinders coming. What are the buoyancy characteristics of the cylinders full & near empty? Trying to get an idea of how to prepare for any buoyancy swings. Anyone here use them? What to expect form them?